Header header
int32 num_coeffs        # order of the polynomial + 1, should match size of x[]
duration segment_time   # duration of the segment
float64[] x             # coefficients for the x-axis, INCREASING order
float64[] y             # coefficients for the y-axis, INCREASING order
float64[] z             # coefficients for the z-axis, INCREASING order
float64[] yaw           # coefficients for the yaw, INCREASING order
